RNP Project

Stage One Report

brisbane green

March 2008
rnp project | brisbane green | stage one report 1

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Brisbane Green Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Safety Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Efficiency Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Environmental Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Future Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Contents
2 rnp project | brisbane green | stage one report

The Brisbane Green Project is a world first 

integration of Required Navigation Performance 

(RNP) approaches and departures into a busy 

international airport. The successful introduction 

of Stage One of the project has laid the foundation 

for widespread adoption of this technology at all of 

Australia’s major airports. This report represents a 

work in progress and we have taken a conservative 

approach to the benefits from this stage of the 

project. The results are, however very encouraging.

Airservices Australia has worked closely with Naverus inc., 

Qantas Airways and the Civil Aviation Safety Authority of 

Australia (CASA) to achieve this successful outcome. Airservices 

is committed to introducing leading edge ATM capability in 

close collaboration with our stakeholders. To date there have 

been RNP approaches deployed to 9 airports across Australia 

including Alice Springs, Ayers Rock, Brisbane, Cairns, Gold 

Coast, Hobart, Canberra, Townsville and Sydney. The broad 

range of environments where RNP is being deployed within 

Australia demonstrates its suitability as a global solution.

At present there are six RNP approach and twelve RNP 

departure procedures deployed at Brisbane. In the first twelve 

months of the project, over 15,500 RNP procedures have been 

conducted including more than 8,000 approaches.

Of the 8000 approaches, 1612 were conducted in night or 

instrument conditions that required an instrument approach.

Key findings for Stage One:

•	 Based on 1612 procedures flown in instrument conditions:

a. Estimated cumulative savings in flight time are 4,200 

minutes achieved through a 17,300NM reduction in 

distance flown;

b. Estimated cumulative savings in jet fuel are more than 

200,000 kg;

c. Estimated carbon dioxide emission reductions of 

650,000 kg;

•	 There was a reduction in aircraft noise impact;

•	 Non-RNP aircraft benefited through reduced delays 

resulting from shorter arrivals for RNP aircraft;

•	 There were no reported occurrences of an RNP capable 

aircraft being denied an RNP clearance upon request;

•	 Comparing the first quarter and the last quarter of Stage 

One of the project, there was a 29% increase in the number 

of flights cleared via an RNP approach;

•	 There was no reduction to airport acceptance rates and a 

slight reduction in average delay;

•	 There have been no weather related go-around events;

•	 There have been no cases of aircraft exceeding the RNP 

design parameters; and

•	 There were no occurrences of the approaches being 

unavailable due to navigation system outages.

The most important insight gained from the project was that 

collaboration between stakeholders is essential.

On behalf of Airservices Australia I would like to thank Naverus 

Inc., Qantas Airways and the Civil Aviation Safety Authority of 

Australia for their contributions and collaboration in Brisbane 

Green. I would also like to acknowledge the outstanding 

efforts of the Airservices project staff and the air traffic 

controllers who have made this project possible. I look forward 

to reporting the results of this ongoing work to you as future 

stages unfold.

Greg Russell

Chief Executive Officer

Airservices Australia

March 2008

Executive Summary
rnp project | brisbane green | stage one report 3

Airservices Australia has a long tradition of 

innovation and collaboration to achieve the 

needs of the aviation industry, particularly in 

the advancement of safety, efficiency and the 

environment. In 2006, Airservices Australia and 

Naverus Inc., in close collaboration with Qantas 

Airways and the Civil Aviation Safety Authority of 

Australia (CASA), began work to implement high 

precision, performance-based instrument approach 

and departure procedures within Australia.

These procedures, based upon Required Navigation 

Performance (RNP), are designed to take advantage of the 

sophisticated navigational capability of modern aircraft.

Initially implemented at terrain challenged locations such 

as Juneau, Alaska, RNP approaches and departures are now 

demonstrating real safety, efficiency and environmental 

benefits at a wide range of airports where modern aircraft 

operate.

Introduction

FIGURE 1.

The rollout of RNP approach and departures is now in 

progress for 15 airports across Australia, including the 

milestone “Brisbane Green” project at Brisbane International 

Airport.

The purpose of Brisbane Green is to determine the most 

effective way to integrate RNP at a busy international airport 

supporting mixed (RNP and conventional) operations. The 

objectives of the project are to:

•	 identify, measure and report the benefits and costs of RNP 

to all stakeholders;

•	 develop ATC and flight crew operating procedures;

•	 identify, resolve and document issues and consequences; 

and

•	 gather a body of data to support the development by 

ICAO of terminal area RNP separation standards.

Under the project, RNP approaches have been deployed 

to Brisbane’s main runways and connected to the Standard 

Arrival (FIGURE 1) and Departure (FIGURE 2) Route structure.
4 rnp project | brisbane green | stage one report

FIGURE 2.

The procedures are approved for use by qualifying aircraft 

in revenue service for day and night operations and in 

all weather conditions. Track mile savings are significant 

compared to the track to the ILS for the same runway. Table 1 

details the savings from arrival to runway threshold.

TABLE 1.

Track Mile Savings – RNP

No. RNP TRACK Miles Saved

1. DAYBO RWY 01 13.1

2. DAYBO RWY 19 4.9

3. AMITY RWY 01 12.8

4. AMITY RWY 19 8.9

5. AMBERLEY RWY 01 Nil

6. AMBERLEY RWY 19 17.3

This report is based on the results from Stage One of the 

project, covering the first year of operation commencing 

January 2007 through to January 2008. As the project 

develops, new aircraft types participate, and complementary 

technologies are introduced, additional reports will 

be published. The intent is to foster collaboration and 

harmonisation with the international community in the 

interests of a safer, environmentally sustainable, more efficient 

and performance-based Air Traffic Management system.

Supporting this intent is Airservices’ commitment to 

collaboration with other stakeholders to achieve an 

environmentally sustainable aviation industry. In February 

2008, Airservices, the United States Federal Aviation 

Administration and Airways New Zealand created the Asia 

and South Pacific Initiative to Reduce Emissions (ASPIRE) 

Partnership.

Under ASPIRE, the three air navigation service providers 

undertook to work closely with airlines and other stakeholders 

in the region, to:

•	 accelerate the development and implementation of 

operational procedures to reduce the environmental 

footprint for all phases of flight on an operation by 

operation basis, from gate to gate;

•	 facilitate world-wide interoperability of environmentally 

friendly procedures and standards;

•	 capitalise on existing technology and best practices;

•	 develop shared performance metrics to measure 

improvements in the environmental performance 

of the air transport system; and

•	 provide a systematic approach to ensure appropriate 

mitigation actions with short, medium and long-term 

results.

Brisbane Green is an example of the work to be advanced 

under the ASPIRE initiative and demonstrates the benefits 

of a collaborative approach.
rnp project | brisbane green | stage one report 5

Airservices Australia

Airservices Australia provides air traffic management 

(ATM) and related airside services to the aviation industry.

Recognised internationally as a leader in the field, Airservices 

is committed to providing safe and environmentally sound 

services across Australia and in the surrounding region.

Each year, Airservices manages air traffic operations for more 

than three million domestic and international passenger 

flights carrying some 47 million passengers. The aviation 

industry also relies on Airservices for aeronautical data, 

telecommunications and navigation services.

The Future

The aviation industry is experiencing unprecedented growth, 

with air traffic in the Asia-Pacific region forecast to double 

in the next decade alone. To provide the necessary airspace 

capacity, while also raising system performance in terms 

of safety, efficiency, security and environment, the aviation 

community must turn to new techniques and technologies – 

an ‘information technology revolution’ for aviation.

No single technology provides all the solutions, and 

Airservices is working to integrate a variety of technologies to 

provide an internationally harmonised, performance-based 

ATM system that caters for a range of aircraft capabilities 

in diverse operating environments. However, one of the 

keystones of the future will be RNP.

RNP, and performance based navigation in general, is 

identified by the International Civil Aviation Organization 

(ICAO) as an enabler of the Global Air Navigation Plan (Doc 

9750). The deployment of RNP is considered as an essential 

element in both the US NextGen and European SESAR plans, 

and the Australian ATM Strategic Plan also notes a major role 

for RNP in delivering the ATM target operational concept.

Airservices is working with Naverus Inc. to deploy RNP across 

Australia. This is a strategic relationship that brings together 

the strengths of both organisations to provide the leading 

edge in air traffic management capability.

Naverus Inc.

Naverus is based in the United States and Australia, and 

specialises in the development of “next generation” navigation 

solutions designed for modern aircraft. Beginning with their 

involvement in the deployment of RNP in Alaska during the 

early 1990’s, the principals of Naverus have pioneered the use 

of terminal area RNP procedures.

Naverus is the world’s leading RNP procedure designer, having 

designed the majority of procedures currently operating in 

revenue service throughout the world.

RNP Technology and Operations

RNP is a way of defining the navigational capability of the 

aircraft, taking into account the performance of the avionics, 

on-board systems and flight characteristics. RNP is a level of 

navigational performance expressed in nautical miles. The 

RNP defines the width of the airspace corridor required for the 

procedure.

Background

RNP utilises the aircraft’s Flight Management System (FMS) to 

integrate numerous sources of position data (including inertial, 

satellite and air data) to provide highly accurate navigation 

with real-time integrity monitoring and alerting. RNP is able 

to provide flexible, accurate and safe instrument approaches 

without the infrastructure demands of conventional approach 

navigation systems. Today it is used at some of the most 

remote and challenging environments in the world, providing 

access and delivering unprecedented improvements to safety.

Significantly however, a number of recent deployments of 

RNP have been at airports where terrain does not constrain 

operations. The ability to curve the approach path has allowed 

the designer to manoeuvre the aircraft around obstacles, 

and restricted or built up areas. This often results in a shorter 

approach when compared to the conventional procedure.

Aircraft Capability

Modern Transport Category aircraft equipped with FMS and 

GNSS are able to meet the airworthiness requirements for RNP 

operations.

RNP capability is usually certified by the manufacturer of the 

aircraft at the time of production. In many cases however, 

older aircraft can be retro-fitted to RNP approach capability 

by undergoing system upgrades.
6 rnp project | brisbane green | stage one report

RNP approach capability is fast becoming a standard feature 

of modern aircraft. In Australia, over 60% of the domestic jet 

transport fleet are certified to RNP0.3 or better.

Australian RNP Implementation

The integration of RNP into day-to-day air traffic flow 

management is a tangible step toward delivering Airservices’ 

Gate-to-Gate and User Preferred Trajectory objectives.

Airservices has offered en-route services based on RNP4 to 

suitably equipped aircraft since 2005, and is now rolling out 

RNP approach and departure procedures for ‘next generation’ 

aircraft. These procedures, based on aircraft performance 

ranging from RNP0.3 down to RNP0.1, are some of the most 

advanced deployed anywhere in the world.

The implementation program for terminal area RNP operations 

in Australia currently includes 15 airports but will be extended 

as benefit and need is determined. It is planned that Australia 

will have an integrated enroute and terminal area RNP 

network by 2010, ranging from non-towered remote airfields 

(such as Ayers Rock in central Australia) to capital cities (such 

as Sydney and Brisbane). To date there have been in excess of 

26,000 RNP approach and departure operations conducted 

nationally.

Completion of Stage One of the Brisbane Green project is a 

milestone within the RNP program as it marks the successful 

integration of RNP approach and departure procedures into 

the air traffic flow management of an international hub.

FINDINGS

1. The broad range of environments where RNP is 

being deployed within Australia demonstrates its 

suitability as a global solution.

2. Projected aviation growth demands evolution to 

satellite and data-link technology to replace legacy 

infrastructure and procedures. 

3. RNP is considered a keystone technology for 

Australia and ensures harmonisation with ICAO and 

Regional strategic plans.

4. RNP maximises use of the onboard navigational 

capability of modern aircraft.

5. The integration of RNP into the ATM system 

provides greater flexibility to balance operational 

requirements with community expectations.

6. Industry collaboration has proven the foundation 

element to ensure benefit realisation from RNP 

deployment
rnp project | brisbane green | stage one report 7

Brisbane

Brisbane Airport is served by a main north south runway 

(01/19) and a shorter crossing east/west runway (14/32). The 

airport has ILS CAT-1 approaches to both ends of the main 

runway.

There are six RNP approach procedures in use to the two 

main runway ends, providing alternatives to the existing ILS 

procedures and visual approach paths. The RNP 0.3 procedures 

provide for a 250ft decision height and were designed by 

Naverus in close collaboration with Airservices’ air traffic 

control specialists.

Project Schedule

The Project is divided into three stages of approximately 12 

months each. Stage One commenced on 18th January 2007 

and involved participation of the Qantas 737-800 fleet; 33 

airframes. To date there have been in excess of 15,500 RNP 

operations conducted at Brisbane with more than 8000 

approaches. This represents approximately 63% of all RNP 

operations nationally.

Stage 2 commenced in early 2008, and includes the Jetstar 

A320/A321 and Air Vanuatu 737NG fleets. To date, this has 

involved an approval process by CASA and the development 

and deployment of crew training for the two airlines.

Stage 3, to commence in 2009, is expected to include Virgin 

Blue Airlines and other international carriers, with additional 

aircraft types.

The Brisbane Green project has provided early 

delivery and demonstration of the safety, economic 

and environmental benefits of RNP. The project also 

provides the opportunity to capture data to support 

safety evidence for development of RNP separation 

standards and rules.

Brisbane International Airport

Based on passenger throughput Brisbane International 

Airport is Australia’s third busiest. During 2007 the airport 

had approximately 173,000 aircraft movements with passenger 

numbers in excess of 17.5 million. This places Brisbane airport 

within the world’s top 100 airports for passenger throughput 

and is comparable in these terms to San Diego USA, Vienna, 

Austria or Osaka, Japan. Twenty-one international airlines and 

five domestic carriers conduct operations at Brisbane Airport, 

using a variety of aircraft ranging from turbo-prop 

and helicopter through to heavy jet operations.

The Brisbane Green Project

Traffic in the Brisbane area is managed by a Terminal Control 

Unit (TCU) and ATC Towers at Brisbane International and 

several nearby airports. Surveillance in the terminal area is 

provided by primary and secondary radar, with upgrade to 

Mode S SSR planned for 2009. Other Airservices projects will 

see Automatic Dependent Surveillance - Broadcast (ADS-B), 

and Advanced Surface Movement Guidance and Control 

Systems (A-SMGCS) deployed in the Brisbane area within the 

next few years.
8 rnp project | brisbane green | stage one report

Procedures Implementation

All RNP procedures at Brisbane have been designed to RNP 

0.3 criteria with their use approved by CASA. Initial design 

commenced some seven months prior to implementation at 

Brisbane. Initial designs were distributed to ATC for review and 

tested in the Qantas 737 flight simulators before being flight 

checked.

An Online Training (OLT) package was developed for air traffic 

controller training. The package targeted the specific elements 

of change within each operational unit. Completion of the 

OLT package was mandatory for all air traffic control personnel 

prior to their participation in the Brisbane Green project.

Qantas pilots undertake theoretical and simulator training to 

qualify for RNP instrument approaches generally. Importantly 

no additional training was required for these RNP qualified 

pilots to participate in the project.

New pilot/controller phraseologies were developed in 

conjunction with CASA and airline participants. These phrases 

were also applicable to other locations where RNP was being 

introduced and were therefore standardised throughout 

Australia. Future enhancements to the ATC automation system 

may eliminate the need for these measures.

FINDINGS

1. Full integration of RNP into the air traffic flow 

management of a busy international hub is 

achievable.

2. Integration of air traffic management considerations 

from commencement of the design stage is 

essential.

3. Stage 2 and 3 of the Project will see a four-fold 

increase of the airframes involved in RNP operations 

at Brisbane.
rnp project | brisbane green | stage one report 9

The approach to safety for the Brisbane Green 

Project has included both qualitative and 

quantitative analysis pre and post implementation. 

Airservices and Qantas both have robust Safety 

Management Systems (SMS) and these systems have 

been fully applied.

Reporting Requirements

CASA has put in place specific reporting requirements 

to ensure timely identification and resolution of issues.

Additionally there has been significant information exchange 

between stakeholders.

Throughout the project, Airservices has recorded 1 instance 

reported as an “event” and 4 instances reported as an 

“incident” via its formal reporting process. All instances were 

fully assessed and where appropriate remedial processes 

put into effect. In all cases, instances were assessed to be of 

a minor nature. Given the number of procedures flown, this 

outcome is considered a very positive result.

Conformance

A study of lateral conformance of Brisbane Green RNP 

operations was also undertaken. Data was collected from 543 

flights, from the period of August 2007 to end January 2008.

Aircraft are required to navigate within 1 x RNP (in this case 0.3 

nautical miles or 556 metres) of the prescribed path 95% of the 

time. It was demonstrated that RNP aircraft are exceeding this 

requirement.

Aircraft conformed to the path prescribed with a standard 

deviation of 0.0224 nautical miles or 41.5 metres and there 

were no instances of aircraft exceeding the approach 

design tolerance. This data will also be used to support a 

safety assessment by ICAO’s Separation and Airspace Safety 

Panel (SASP) for development of new RNP based separation 

standards.

Safety Analysis

Non-normal Operations

RNP procedures deployed in Australia make provision for 

emergency operations including engine and other system 

failures at any point in the approach or departure. The safe 

extraction of a disabled aircraft is provided with an alternative 

flight path which automatically steers the aircraft over the 

lowest terrain and delivers it to an altitude where it can safely 

return to land.

In terrain challenged airports like Queenstown, New Zealand, 

Cairns and Canberra this capability has reduced the workload 

on pilots in an emergency and dramatically raised the safety 

of operations. RNP is valued as an effective weapon in the 

fight against the Controlled Flight into Terrain (CFIT).

FINDINGS

1. A transparent and collaborative approach to safety 

activities between the airline, ANSP and regulator 

are a foundation to project success.

2. A total of 1 event and 4 incidents were reported for 

more than 8000 approaches and 7000 departures.

3. 100% compliance within the RNP navigation 

requirement has been achieved.

4. Inherent characteristics of RNP support safety 

improvements.
10 rnp project | brisbane green | stage one report

For the 12 months of Stage One, more than 200,000 

kg of fuel was saved during RNP approaches. 

For aircraft conducting an instrument approach, 

RNP can have a positive impact on delays and 

fuel consumption through track shortening and 

Continuous Descent Arrivals (CDA).

Reduced Flight Distance

A conventional instrument approach such as an ILS is 

constructed by extending a line from a navigation aid (on the 

ground) to a point in space where the approach commences.

In the case of the ILS, this point is approximately 10NM from 

the runway. An RNP approach is not dependent upon the 

location of ground aids and is constructed as a series of 

straight and curved segments. The length of the straight 

segment immediately before the runway threshold may be 

as short as one mile. This feature allows the designer to curve 

the approach around obstacles, restricted and noise sensitive 

areas and to “abbreviate” the approach to achieve a reduction 

in the distance flown by the aircraft as it approaches to land.

During Stage One of the Brisbane Green Project the total 

number of track miles saved is estimated to exceed 17,300 

nm (approximately 4,200 minutes of flight time). This result 

is based upon the instances where a participating B737-800 

was able to conduct the RNP approach where otherwise an 

ILS approach would have been required. This has resulted in 

approach tracks being shortened by up to 17.3NM.

Track shortening at the end of the approach has far more 

impact than track shortening at the beginning of the 

approach because the rate of fuel consumption of a jet engine 

increases as the aircraft descends and configures for landing.

Efficiency Analysis

Reducing fuel consumption during arrival and descent is a key 

efficiency and environmental objective. The job of the air traffic 

controller is to safely separate aircraft. Aircraft can be separated 

both laterally and vertically and therefore it is common for 

arriving aircraft to level off at intermediate altitudes as air traffic 

controllers provide vertical separation from aircraft passing 

below. For the aircraft to interrupt its descent, thrust must be 

applied and that means more fuel is burned.

Continuous Descent Arrival

A CDA is one where the vertical path of the aircraft is 

uninterrupted and optimised for use of idle thrust. An RNP 

approach is designed to allow the FMS to manage the energy 

during descent, eliminating unnecessary level segments. The 

accuracy of navigation and speed control during the descent 

also allows the air traffic controller to predict the progress of 

the aircraft and aids in the sequencing of landing aircraft. For 

the controller, the need to intervene in the descent or the 

navigation of the aircraft is greatly reduced.

As a result, RNP aircraft arriving into Brisbane are able to 

conduct a CDA from the top of descent thereby allowing the 

aircraft to virtually glide at idle thrust for approximately the last 

20 minutes of flight.
rnp project | brisbane green | stage one report 11

Airspace Capacity

It was found that the time saved through an RNP approach 

was consistent and predictable, and that the accumulation of 

time saved by an RNP approach flows on to following aircraft 

in the sequence. This generates savings for all flights into an 

airport where RNP approaches are deployed whether aircraft 

are RNP or Non-RNP and provides the potential for increased 

throughput of arriving aircraft to the airport.

FIGURE 3 shows the predictability of RNP approach paths 

(green) by contrast with the significant variation to flight path 

for conventional procedures and the associated controller 

workload.

FIGURE 3.

Use of RNP Procedures

The suitability of RNP approaches in normal airport operations 

was identified as a success measure for Stage One, specifically 

how often the controller was able to grant an RNP approach 

as opposed to an ILS or visual approach was assessed. To 

date there has been no reported instances of an RNP capable 

aircraft being denied an RNP approach.

Comparing the first and last quarter of Stage One of the 

project there was a 29% increase in the number of flights 

cleared via an RNP approach.

Airport Capacity

Another measurement of success for the project was the 

impact of RNP approaches on airport capacity. Analysis from 

the month immediately prior to commencement of Stage 

One (December 2006) compared to the final month of this 

stage (December 2007) indicates that no reduction to airport 

acceptance rates has occurred and indeed, there was a 

slight overall reduction in average delay of 28 seconds. This 

initial finding will be the subject of more detailed analysis 

throughout later stages.

This is a very encouraging outcome and indicates that 

in Brisbane, RNP has rapidly assimilated into the ATC 

environment. The presence of an RNAV STAR system and 

flow management protocol has resulted in a reduced need 

for tactical intervention through radar vectoring. This has 

facilitated a high and increasing level of RNP approach 

clearances.

The potential accumulated benefit to airport capacity 

is substantial and throughout later stages of the project 

empirical data will be collected to measure the impact of RNP 

on the overall capacity of the terminal airspace.

1. The RNP approaches at Brisbane provided shorter 

approaches by up to 17.3 NM.

2. The total number of track miles saved during Stage One 

is estimated to exceed 17,300NM; 

3. Identified fuel savings are in excess of 200,000 kg.

4. Flight time savings for arrivals exceeded 4,200 minutes.

5. The RNP approaches at Brisbane provided greater trajectory 

predictability allowing reduced controller intervention.

6. There has been no reduction to airport acceptance rates 

and a slight overall improvement to average delay by 28 

seconds.

7. RNP facilitates a CDA which provides for significant fuel 

savings.

8. Non-RNP flights following an RNP aircraft gain benefit 

through less delay derived from the shorter RNP 

approach.

FINDINGS
12 rnp project | brisbane green | stage one report

The aviation industry has been managing its 

environmental impacts for many years, and aircraft 

noise is regularly raised in public debate about the 

operation and expansion of airports. Aviation’s 

contribution to greenhouse gas emissions, although 

small when compared to others, is anticipated to 

grow. Environmentally sound decision-making is 

therefore critical to the long-term development 

of the industry.

More broadly, Australia has committed to working on climate 

change issues. In January 2006, Australia, China, India, Japan, 

Republic of Korea and the United States launched the Asia 

Pacific Partnership on Clean Development and Climate (AP6) 

and in December 2007 Australia became a signatory to the 

Kyoto Protocol to the United Nations Framework Convention 

on Climate Change. Airservices’ partnership with the FAA and 

Airways New Zealand in ASPIRE is part of this commitment.

The aviation industry has responded to the issue of emissions 

with the International Air Transport Association (IATA) and 

ICAO specifically encouraging the implementation of new 

ATM practices and technologies in the management of 

aviation’s environmental impacts.

Carbon Dioxide (CO2)

Every kilogram of fuel saved saves just over three kilograms 

of CO2 emissions. By comparing airline fuel consumption 

data with airport movement records, it has been possible to 

determine, with a high degree of confidence, that Stage One 

of Brisbane Green has saved more than 650,000 kg of CO2 

emissions.

This estimate has been based upon the ICAO recommended 

methodology for converting minutes of flight to CO2 

emissions. Further analysis is underway and based on actual 

fuel usage it indicates that for some approaches the emissions 

savings may be considerably higher.

But this is the beginning. This remarkable result has been 

achieved by just 33 aircraft in 12 months of operations. It is 

expected that Stage Two will significantly improve on this 

result with the phased inclusion of more participant aircraft 

over the coming 12 months.

Nitrous Oxide (NOx)

Nitrous Oxide is the third largest greenhouse gas contributor 

to overall global warming, behind carbon dioxide and 

methane. Nitrous Oxide emissions by jet aircraft are correlated 

to the thrust produced by the engine. An approach without 

level flight segments, that does not require additional thrust 

to maintain an altitude during the approach, can minimise the 

production of NOx.

Level segments have traditionally been used to allow aircraft 

to lose speed, intercept the instrument approach, sequence 

flows to the runway or facilitate vertical segregation of routes.

RNP procedures offer alternative means to achieve these goals, 

while providing a CDA from high-altitude cruise to the runway.

FIGURE 4 depicts actual data for an RNP and Non-RNP 

approach in Brisbane within 15mins Actual Time of Arrival (ATA).

FIGURE 4.

Environmental Analysis

In general terms this data supports our expectation that NOx 

will be significantly reduced through the introduction of RNP.

Stage Two of the project will see the capture and analysis of 

further detailed data.

Noise

Aircraft noise has been a major focus in Australia and 

elsewhere in the world, particularly since the development of 

commercial jet aircraft. Technological developments in the 

last 40 years have significantly reduced the noise impact from 

aircraft on communities in the vicinity of airports. In that time 

perceived noise from individual aircraft has been reduced by a 

factor of four.

The introduction of stricter Chapter 4 noise requirements in 

January 2006 have made little, if any, difference to the noise 

levels around Australian airports due to the modern domestic 
rnp project | brisbane green | stage one report 13

fleet, most of which were already meeting the Chapter 4 

standards. As a result, noise impacts around major Australian 

airports have been found to increase largely proportional to 

air traffic increases. Improved ATM techniques will be pivotal 

in managing noise in the short to medium term.

FIGURE 5.

FIGURE 7 demonstrates lower noise levels for RNP flights at 

the Kedron noise monitor indicating that these aircraft are at 

higher altitude than typically flown during a visual approach.

This shows that very few RNP flights generated noise above 

75dB at Kedron.

FIGURE 7.

Noise footprints for the RNP procedures were estimated by 

AVTECH, Sweden AB (FIGURE 5). This indicated that the 70 dB 

and 75 dB footprints would be significantly reduced in size, 

and the accuracy of the RNP design allowed the procedure 

to be placed over non-residential areas, such as the Brisbane 

River.

FIGURE 6 shows the flight paths for RNP (green) and Non-RNP 

(red) aircraft approaching Brisbane runway 01 via the “River” 

noise abatement procedure. The RNP path ensures that the 

low level final approach is conducted over the river and 

industrial areas.

FIGURE 6.

Noise forecasts for RNP and conventional approaches (FIGURE 

5) have been validated using noise monitors at Kedron and 

Bulimba (FIGURE 6) and other locations.

FINDINGS

1. RNP approach and departure procedures provide 

practical means to reduce CO2, NOx and noise 

emissions.

2. The Brisbane Green Project has saved 650,000 kg 

of CO2 emissions in the first year alone.

3. Expectations of reduced NOx emission levels are 

supported by experience of uninterrupted CDA 

during RNP approaches.

4. The flexibility and accuracy of RNP operations 

allows for noise footprints to be placed over nonresidential areas.
14 rnp project | brisbane green | stage one report

Stage One of the RNP Project – Brisbane Green has been 

successful and has exceeded the expectations of the 

stakeholders. Data gathered in Stage One has validated the 

benefits which can be realised by the implementation of 

performance based navigation technology.

The success of the Brisbane Green project and the 

qualifications of benefits have provided Airservices Australia 

with the confidence to commit to the deployment of RNP 

across Australia. Brisbane Green is a model for Airservices and 

other ANSPs to build on in the development of performance 

based navigation programs around the world.

A large body of high quality data has been collected from the 

project validating the benefits of RNP approach and departure 

operations. Stages Two and Three will continue to capture this 

data and more, while also focusing upon the introduction of 

additional aircraft types and complementary technologies.

This will further establish the business case for the integration 

of RNP approach and departures within complex air traffic 

management environments.

By working with airspace users, regulators, other air navigation 

service providers and leading edge ATM capability providers 

such as Naverus, Airservices will continue to advance the 

Australian CNS/ATM system. Through our RNP implementation 

program, Airservices and stakeholders will deliver:

•	 Increased safety in all weather conditions;

•	 Lower fuel consumption and greenhouse gas emissions;

•	 Reduced noise for airport communities; and

•	 Reduced impost of weather and terrain upon operations.

Airservices Australia wishes to acknowledge the contributions 

of Naverus Inc., Qantas Airways and the Civil Aviation Safety 

Authority of Australia to the success of the Brisbane Green RNP 

project.

Further Information:

Airservices Australia

Wayne Emery

General Manager, Business Development

t: +61 2 6268 4057

wayne.emery@airservicesaustralia.com

www.airservicesaustralia.com

Future Steps

Naverus

t: +1 253 867 3900

info@naverus.com
rnp project | brisbane green | stage one report 15

ABBREVIATION DETAIL

ANSP Air Navigation Service Provider

AP6 Asia Pacific Partnership on Clean Development and Climate

ATC Air Traffic Control

ATM Air Traffic Management

ASPIRE Asia and South Pacific Initiative to Reduce Emissions

CASA Civil Aviation Safety Authority (Australia)

CDA Continuous Descent Arrival

CFIT Controlled Flight Into Terrain

CNS Communication, Navigation and Surveillance

CO2 Carbon Dioxide

dB Decibel

FMS Flight Management System

GNSS Global Navigation Satellite Systems

IATA International Air Transport Association

ICAO International Civil Aviation Organization

ILS Instrument Landing System

Kg Kilogram

NM Nautical Mile

NOx Nitrous Oxide

OLT Online Training

RNAV Area Navigation

RNP Required Navigation Performance

RWY Runway

SASP Separation and Airspace Safety Panel (ICAO)

SMS Safety Management System

STAR Standard Arrival Route

Glossary